Restore naive filtering to rest end point.

src/wp-includes/rest-api/endpoints/class-wp-rest-font-faces-controller.php

@@ -856,21 +856,7 @@ protected function sanitize_src( $value ) {
 	 */
 	protected function handle_font_file_upload( $file ) {
 		add_filter( 'upload_mimes', array( 'WP_Font_Utils', 'get_allowed_font_mime_types' ) );
-
-		/*
-		 * Set the upload directory to the fonts directory.
-		 *
-		 * wp_get_font_dir() contains the 'font_dir' hook, whose callbacks are
-		 * likely to call wp_get_upload_dir().
-		 *
-		 * To avoid an infinite loop, don't hook wp_get_font_dir() to 'upload_dir'.
-		 * Instead, just pass its return value to the 'upload_dir' callback.
-		 */
-		$font_dir       = wp_get_font_dir();
-		$set_upload_dir = function () use ( $font_dir ) {
-			return $font_dir;
-		};
-		add_filter( 'upload_dir', $set_upload_dir );
+		add_filter( 'upload_dir', 'wp_get_font_dir' );
 
 		$overrides = array(
 			'upload_error_handler' => array( $this, 'handle_font_file_upload_error' ),
@@ -888,7 +874,7 @@ protected function handle_font_file_upload( $file ) {
 
 		$uploaded_file = wp_handle_upload( $file, $overrides );
 
-		remove_filter( 'upload_dir', $set_upload_dir );
+		remove_filter( 'upload_dir', 'wp_get_font_dir' );
 		remove_filter( 'upload_mimes', array( 'WP_Font_Utils', 'get_allowed_font_mime_types' ) );
 
 		return $uploaded_file;